The basic system by which any two like objects can be compared is referred to the system of weights and measures, which establishes standards for measuring various parameters such as length, weight and liquid. Each parameter may have a number of different dimensional or unit designations which represent a measurement of that parameter. For example, the parameter liquid may be expressed in pints, quarts, gallons, and so on. These related unit representations of a given parameter so pervade the everyday activities of the average person that a spontaneous awareness of their significance is necessary to deal with day to day affairs at work, at home and in purchasing activities.
Most countries throughout the world have adopted an international system of weights and measures referred to as the metric system. The United States, however, owing to its historical ties to Great Britain, has adopted and continues to use a system of weights and measures based upon the early British system. As opposed to the arbitrary British system, the metric system was established based upon scientific criteria. It establishes a basic unit for each parameter as well as equivalents thereof based upon some multiple of 10 or division by a multiple of 10 of the basic unit. Thus looking to the basic unit of length as the meter, the basic unit of liquid as the liter, and the basic unit of mass and weight as the gram, the most commonly used metric measurements are as follows:
______________________________________ LENGTH UNIT NUMBER OF METERS ______________________________________ kilometer 1,000 hectometer 100 decameter 10 meter 1 decimeter 0.1 centimeter 0.01 millimeter 0.001 LIQUID UNIT NUMBER OF LITERS ______________________________________ kiloliter 1,000 hectoliter 100 decaliter 10 liter 1 deciliter 0.10 centiliter 0.01 milliliter 0.001 MASS and WEIGHT UNIT NUMBER OF GRAMS ______________________________________ kilogram 1,000 hectogram 100 decagram 10 gram 1 decigram 0.10 centigram 0.01 milligram 0.001 ______________________________________
Both for these reasons and due to the need for international unformity, the United States has commited itself to a policy of promoting the adoption of the metric system in this country. See the Metric conversion Act of 1975, 89 Stat. 1007.
In spite of the long term advantages to be gained by a changeover to the metric system, the average person is now faced with the prospect of having a system of weights and measures with which he is totally familiar replaced with one with which he is equally unfamiliar. As opposed to the everyday instinctive knowledge by which the significance of a relative unit of measurement of the American system is understood because of education and experience (for example, one is quite familiar with the fact that one yard is larger than one foot, and that in fact three feet constitute one yard), the average person, upon introduction of the metric system, may find himself confronted by an apparent deluge of confusing dimensional designations.
More specifically, the problems facing the average person with the adoption of the metric system occur when he sees a measurement, for example, of one decimeter, and, due to his unfamiliarity with the metric system, may incur difficulty in picturing just what length that measurement refers to relative to other metric measurements. It is, therefore, desirable to provide such a person with a ready means for comparing such a measurement with its metric equivalents. Moreover, since the measurements to be encountered will have a number of possible parameters each having a separate system of units, it is desirable to provide a ready means wherein a measurement in any one of these parameters may be compared with the metric equivalent units within its same parameter.